So I am planning on buying a Sony dcx - s200x or s300btx and a modifry dci interface but am confused if I need to get the extra harness or not. I tried sending an email to their customer service but haven't gotten an answer all day. I want to get everything purchased tomorrow so I can install this weekend.

 

you do want an adapter harness of some sort - the headunit will come with a harness that plugs
into the headunit and has raw wires, and rather than cutting the car's connector off and splicing
wires, you will splice the Sony harness wires to the adapter harness wires, and then you can simply
plug the connectors together.
You can use a generic Honda adapter harness - depending on where you buy your headunit, it may
even come with one - but I'd recommend buying Modifry's as it is definitely has all the proper wires.
Some generic harnesses don't have the s2000-specific dash switch wires.

 

That's what I'm confused about.. On Crutchfield they include the wiring harness for the headunit, but on modifry they have the dci thing for the steering wheel controls but I see they sell a harness too. Is that their harness for the stereo to factory harness? or the steering wheel controls? I know I need the more expensive part but there is another part, the step two or three when you're ordering the part.

 

it's an adapter harness that plugs into the car's harness, and then is connected to the headunit's harness
as well as to the DCI. If Crutchfield includes one of these already, you don't need Modifry's, although it
may be that it lacks one or both of the s2000-specific wires - one that goes to the mute switch, and/or one
that goes to the rest of the dash switches. If it is missing these wires, it likely has a few extra unused
wires, for instance rear speaker wires if you don't have rear speakers, which can be moved to the correct
places in the adapter harness, but it's an extra bit of (possibly tricky) work.
Maybe someone who has bought from Crutchfield recently knows if the included harness has those wires or not.

 

It does not. I got one with my new deck, and also bought Modifry's, and once I saw the two next to each other, I was like "Ohhhhhhhh, I see!" You can do the install with the Crutchfield one, but in my opinion it's well worth the money to get the Modifry one unless you're on a super tight budget. It just makes it much easier.

 

I see, looks like I found a page on their website that explains the harness a little bit better. I somehow missed that the other day..

 

Not sure why this is so common but the DCI and the harness are 2 separate things. People quite often call the DCI a harness for some reason.

You need both.

 

Ditto. I have the DSX-300, and trust me, you should buy Modifry's harness if you're getting the DCI. It's really cheap anyway, so it shouldn't be a big deal. Once you solder the DCI, Modifry harness, and Sony-supplied harness together, it's plug and play. (I know, it takes a lot longer to get there than w/ Alpine, but the HU is worth the extra trouble)

 

Well I tried to order the modifry harness but its out of stock for the Sony. In my haste I ordered a Kenwood H/U and the Kenwood DCI and harness. Guess ill see how I like it, oh and I am used to splicing wires to get stereos installed, its part of the fun .